The Food and Drug Administration of the United States (FDA) against JohnsonThe company's COVID-19 Vaccine profile has been revised to warn of the risk of rare immune system diseases.

FDA said in a statement on Monday that it had received 100 reports of Guillain-Barr é Syndrome, a rare disease in which the immune system attacks the nervous system, after receiving Johnson's vaccine. So far, about 12.8 million Americans have been vaccinated with Johnson's single-dose vaccine.

Of the patients, 95 need to be hospitalized and one has died, FDA said. Although there is evidence of a link between vaccination and the disease, the agency says the data is not sufficient to clearly conclude that the Johnson vaccine caused the disease.

According to the revised information page, the relevant symptoms began to appear within 42 days of injection of Johnson vaccine.

According to the United States Centers for Disease Control and Prevention (CDC), the reported cases are mainly men over the age of 50, and the disease begins about two weeks after vaccination. CDC said the issue would be discussed at the upcoming meeting of the Vaccine Advisory Committee.

According to FDA, between 3000 and 6000 people suffer from Guillain-Barre syndrome each year, most of whom recover. The agency says some vaccines can lead to increased morbidity, including seasonal flu and shingles vaccines.

Symptoms usually occur within days or weeks after respiratory or gastrointestinal virus infection and can lead to mild muscle weakness and paralysis in severe cases.

Despite the new warning, CDC said that the incidence of serious adverse reactions to COVID-19 vaccine is still very small, and people aged 12 and above are advised to be vaccinated. The benefits of Johnson's vaccine in preventing COVID-19 significantly outweigh the known and potential risks, FDA said.